Feed use intensification and technical efficiency of dairy farms in New Zealand

In recent years, the traditionally pasture‐based dairy farms in New Zealand have become more intensive by using higher proportions of supplementary feed. This trend has been attributed to a range of factors, such as productivity enhancement, overcoming pasture deficits and the improvement of body condition scores. However, there is a lack of knowledge as to how feed use intensification affects the technical efficiency of dairy farms in New Zealand. This paper addresses the research gap by estimating the impact of feed use intensification on the technical efficiency of New Zealand dairy farms, using a fixed effects stochastic production frontier model and a balanced panel of 257 farms from 2010 to 2013. The empirical results show that technical efficiency on New Zealand dairy farms is positively and significantly influenced by feed use intensification, herd size and milking frequency.     

Public acceptance of and heterogeneity in behavioral beach trip responses to offshore wind farm development in Catalonia (Spain)

A combined travel cost – contingent behaviour survey of residents and tourists in Catalonia is conducted on-site to examine the effects on beach recreational demand of developing an offshore wind farm (OWF) project. The survey considers four potential OWF scenarios with different degrees of visual impact. We allow for heterogeneity in trip preferences among individuals and control for on-site sampling through the use of a random parameters negative binomial (RPNB) model and a Multivariate Poisson log-normal (MPLN) model, respectively. The welfare measures derived from the RPNB model relate to the current beach users only, whereas those from the MPLN model refer to the general population of residents and tourists in Catalonia. The results show the importance of the specific place of location of the OWF project and how the installation of wind turbines would significantly decrease the demand for trips, depending on their degree of visual impacts, leading to a substantial welfare loss. However, the results also show that the project mainly would cause a displacement of trips to other beaches within Catalonia rather than outside Catalonia and that the welfare per trip measures generated by the RPNB and MPLN models substantially differ. Policy implications of these findings are discussed.     

港口物流机械风载荷计算方法研究

风载荷的研究在港口物流机械的设计和计算中占据着重要的地位,主要是因为它对起重机结构强度和稳定性的影响极其重要。而风载荷的确定通常由风力系数、挡风折减系数、有效迎风面积以及相应条件下的风压确定。     

困难农场科学发展的实践与思考

困难农场发展的滞后已严重制约广西农垦管区的经济社会发展,加快困难农场发展步伐是实现管区科学发展、和谐发展和跨越发展的必然选择。＂十一五＂期间,广西农垦管区实施了扶贫帮困行动计划,使困难农场走出低谷,走上良性发展轨道。文章以广西农垦国有王灵农场为例,总结困难农场科学发展的工作实践,提出今后工作思考。     

困难农场科学发展的实践与思考

困难农场发展的滞后已严重制约广西农垦管区的经济社会发展,加快困难农场发展步伐是实现管区科学发展、和谐发展和跨越发展的必然选择。十一五期间,广西农垦管区实施了扶贫帮困行动计划,使困难农场走出低谷,走上良性发展轨道。文章以广西农垦国有王灵农场为例,总结困难农场科学发展的工作实践,提出今后工作思考。     

石化企业仪表风空气干燥装置的改造

针对目前一些石化企业中旧的设备在运行中出现的问题,通过使用PLC控制改造后进行优化控制,以达到石化行业中生产装置的安全、稳定、长期、满载、优质运行的要求。介绍了仪表风空气干燥装置的可编程控制器控制改造。     

金紫山风电场一期工程风机基础设计

风电场的风力发电机组基础形式主要有扩展基础、桩基础和岩石锚杆基础,具体采用哪种基础应根据建设场地地基条件和风力发电机组上部结构对基础的要求确定。文章以广西资源县金紫山风电场一期工程为例,介绍山区风力发电机组基础的设计。     

我国风机制造业竞争力强度研究——基于景气指数分析法

利用景气指数分析法并结合扩散指数研究了2003—2009年我国风机制造业竞争力强度。得出结论:我国风机制造业已结束混乱竞争局面,正逐步走向但还没有达到有序竞争阶段,产业步入成长期。     

天津承接离岸服务外包的SWOT分析及对策研究

离岸服务外包是全球范围内掀起的新一轮产业转移浪潮。文章深入分析了天津服务外包产业的发展现状,采用SWOT分析法总结天津承接离岸服务外包业的优势、劣势、机遇和挑战,分别从政府和企业的角度提出天津发展离岸服务外包的对策及建议。